1. Field of Invention
The present invention belongs to the technical field of road construction, and more particularly to a hot recycling heating method and device for old asphalt mixture.
2. Description of Related Arts
Hot recycling of old asphalt mixture is a common way of recycling asphalt in road construction.
The existing method of hot recycling of old asphalt mixture principally consists of a drying drum heating mode wherein the sieved and cold-blended old asphalt mixture is conveyed to a drying drum that is compatible in use with a gap-type asphalt mixture mixing plant, convection or convection/radiation-based heat exchange is accomplished between the old asphalt mixture and the burner-resulting in high-temperature fumes that heat the old asphalt mixture in the drying drum, and the heated old asphalt mixture is metered, then conveyed into an agitator pot and finally agitated and mixed with the heated materials such as mineral aggregate, new asphalt and mineral powder, so as to generate a recycled asphalt mixture.
In the aforementioned hot recycling mode, the hot recycling heating method for the old asphalt mixture is implemented inside the drying drum; the burner-resulting high-temperature fumes in the drying drum have an extremely high temperature, so the asphalt that covers the mineral aggregate like a thin film undergoes intensive aging and generates a large amount of asphalt volatiles, i.e. asphalt fumes.
The pavement performance of the asphalt in the existing method hot recycling mode is greatly diminished because of contact and heat exchange between the old asphalt mixture in the drying drum. Plus the high-temperature fumes produced in the drying drum causes severe environmental pollution